12 oz canteen with 3 oz snack compartment built into the lid (15 oz total). Twist the lid to reveal and hide the straw and to reveal and hide the opening to the snack compartment. Lid screws on for secure closure.

The lid has the following 3 positions:Drinking - straw up with snack compartment closedSnacking - straw down with snack compartment openClosed - straw down and snack compartment closed